Class Predicates

谓词组工具方法

Inheritance

System.Object

Predicates

Namespace: DapperDal.Predicate

Assembly: DapperDal.dll

Syntax

public static class Predicates : object

Methods

Between<T>(Expression<Func<T, Object>>, BetweenValues, Boolean)

Factory method that creates a new IBetweenPredicate predicate.

Declaration

public static IBetweenPredicate Between<T>(Expression<Func<T, object>> expression, BetweenValues values, bool not = false)where T : class

Parameters

Type	Name	Description
Expression<Func<T, System.Object>>	expression
BetweenValues	values
System.Boolean	not

Returns

Type	Description
IBetweenPredicate

Type Parameters

Name	Description
T

Exists<TSub>(IPredicate, Boolean)

Factory method that creates a new IExistsPredicate predicate.

Declaration

public static IExistsPredicate Exists<TSub>(IPredicate predicate, bool not = false)where TSub : class

Parameters

Type	Name	Description
IPredicate	predicate
System.Boolean	not

Returns

Type	Description
IExistsPredicate

Type Parameters

Name	Description
TSub

Field<T>(Expression<Func<T, Object>>, Operator, Object, Boolean)

Factory method that creates a new IFieldPredicate predicate: [FieldName] [Operator] [Value]. Example: WHERE FirstName = 'Foo'

Declaration

public static IFieldPredicate Field<T>(Expression<Func<T, object>> expression, Operator op, object value, bool not = false)where T : class

Parameters

Type	Name	Description
Expression<Func<T, System.Object>>	expression	An expression that returns the left operand [FieldName].
Operator	op	The comparison operator.
System.Object	value	The value for the predicate.
System.Boolean	not	Effectively inverts the comparison operator. Example: WHERE FirstName <> 'Foo'.

Returns

Type	Description
IFieldPredicate	An instance of IFieldPredicate.

Type Parameters

Name	Description
T	The type of the entity.

Group(GroupOperator, IPredicate[])

Factory method that creates a new IPredicateGroup predicate. Predicate groups can be joined together with other predicate groups.

Declaration

public static IPredicateGroup Group(GroupOperator op, params IPredicate[] predicate)

Parameters

Type	Name	Description
GroupOperator	op	The grouping operator to use when joining the predicates (AND / OR).
IPredicate[]	predicate	A list of predicates to group.

Returns

Type	Description
IPredicateGroup	An instance of IPredicateGroup.

Property<T, T2>(Expression<Func<T, Object>>, Operator, Expression<Func<T2, Object>>, Boolean)

Factory method that creates a new IPropertyPredicate predicate: [FieldName1] [Operator] [FieldName2] Example: WHERE FirstName = LastName

Declaration

public static IPropertyPredicate Property<T, T2>(Expression<Func<T, object>> expression, Operator op, Expression<Func<T2, object>> expression2, bool not = false)where T : class where T2 : class

Parameters

Type	Name	Description
Expression<Func<T, System.Object>>	expression	An expression that returns the left operand [FieldName1].
Operator	op	The comparison operator.
Expression<Func<T2, System.Object>>	expression2	An expression that returns the right operand [FieldName2].
System.Boolean	not	Effectively inverts the comparison operator. Example: WHERE FirstName <> LastName

Returns

Type	Description
IPropertyPredicate	An instance of IPropertyPredicate.

Type Parameters

Name	Description
T	The type of the entity for the left operand.
T2	The type of the entity for the right operand.

Sort<T>(Expression<Func<T, Object>>, Boolean)

Factory method that creates a new Sort which controls how the results will be sorted.

Declaration

public static ISort Sort<T>(Expression<Func<T, object>> expression, bool ascending = true)

Parameters

Type	Name	Description
Expression<Func<T, System.Object>>	expression
System.Boolean	ascending

Returns

Type	Description
ISort

Type Parameters

Name	Description
T